This research is a randomized clinical trial of specialized training for foster parents. Foster parents provide primary mental health services to foster children who have multiple problems including histories of abuse, neglect, and parental drug abuse. As a result of problematic caregiving histories, foster children often develop patterns of interacting which make it difficult for them to develop trusting relationships with their foster, adoptive, or biological parents. The effects of these interaction patterns can be quite damaging, contributing to children's failure to rely effectively on caregivers, and behavioral and emotional problems. The proposed study assesses the effectiveness of an intervention program developed to help caregivers understand and change the strategies children use for coping with problematic caregiving histories. Foster parents of infants will be randomly assigned to an experimental group, in which caregivers receive specialized training, or to a control group. Caregivers will receive the interventions at the time of placement and replacement, and when children are 12, 18, 24, and 30 months of age. Caregivers receiving the specialized training are expected to be more sensitive to their children's needs, and their relationships with their infants are expected to be more secure and effective compared to caregivers in the control group. Infants in the experimental group are expected to show fewer behavioral, emotional, and social problems than infants in the control group. Specific aims are to: 1) experimentally evaluate the effectiveness of a specialized intervention program for foster infants' caregivers; 2) examine particular characteristics of children and parents that may affect treatment outcomes; and 3) assess naturalistically the effects of timing and frequency of foster care placements, on children's adjustment to subsequent caregivers.